The population of mound nests of Formica opaciventris, under observation since 1957, was again examined. Since 1957 the total population has declined 16% with corresponding decrease in the proportion of more active mounds. Average mortality rate is 10.4%; average birth rate, 9.9%. Brood was present in 85% of mounds. Project Number 80.
"Social Organization Among Colonies in Ants,"
Jackson Hole Research Station Annual Report: Vol. 1964
, Article 13.
Available at: https://repository.uwyo.edu/jhrs_reports/vol1964/iss1/13